EDITORS' NOTE: Reuters and other foreign media are subject to Iranian restrictions on their ability to film or take pictures in Tehran.

A man holds a placard during a protest gathering in front of the British embassy in Tehran December 2, 2009. The gathering was held to ask British government to return Arash Hejazi, who fled to London after being identified as a witness in the death of Neda Agha-Soltan. REUTERS/Morteza Nikoubazl (IRAN CONFLICT CRIME LAW POLITICS)